Friday, May 27, 2005

Mars Global Surveyor (MGS), the oldest working spacecraft orbiting the red planet, is taking some time to check out the newest kids in the neighborhood. On April 20th, astronomers used the veteran's Mars Orbiter Camera to take pictures of another spacecraft: Mars Express. The two orbiters were about 250 kilometers (155 miles) apart when MGS shot the picture. Three images were combined to provided this view of the 15-meter-wide European craft. In the middle are the orbiter's cameras and what is most likely a reflection from the craft's high-gain antenna. The wings are reflections from the solar panels.

Courtesy NASA/JPL/MSSS.

The next day MGS continued its snooping game by capturing high-resolution images of another spacecraft: NASA's Mars Odyssey. The image was captured from about 90 kilometers away. The 6-meter-long boom holding the craft's Gamma Ray Spectrometer is quite visible, as is Mars Odyssey's high-gain antenna, seen as the top bright spot on the right side.

These are the first-ever pictures of a Martian orbiter taken from another Martian orbiter.

Thursday, May 26, 2005

Why is America returning to the moon, and what does the new “vision” for NASA mean for science?

THE name Eugene Cernan means little to most people, though space nerds may remember it. Along with more famous astronauts such as Neil Armstrong, Mr Cernan played a role in the annals of space exploration by walking on the moon. And he was the last to do so, which is fame of a sort. If George Bush gets his way, however, this claim to fame may vanish. That is because Mr Bush has a vision. He wants humans to return to the moon by 2020. The questions are, first, what for? And, second, having been given such orders, what will Mike Griffin, the new boss of America's space agency, NASA, do to execute them?

The second question seems more urgent because Mr Bush's initial goal is to reinvigorate an agency that is facing both the withdrawal of its flagships, the still-grounded space shuttles, and the failure of the international space station to deliver anything remotely approaching an interesting scientific result.

He played upon a ladle

Some of the details about how Dr Griffin proposes to execute Mr Bush's vision emerged at the International Space Development Conference held in Washington, DC, last week. For example, NASA announced a $250,000 prize for extracting oxygen from the lunar regolith.

Where the Earth has soil, other rocky bodies in the solar system have regolith. Soil is, in part, the product of biological activity (all those earthworms, and so on). Regolith is a fine powder formed by a constant rain of small meteorites that breaks up the rocks at the surface. Analysis of lunar regolith brought back by Apollo missions shows it contains lots of oxygen. Existing ways of extracting this oxygen, however, are too slow to be useful. So a competition called the MoonROx challenge is being mounted. The prize will go to the first person to come up with a way of quickly extracting an adequate amount of oxygen from simulated lunar regolith (volcanic ash is being used as a stand-in).

Oxygen, though, is only the beginning, according to Paul Spudis, a planetary scientist at Johns Hopkins University who was a member of the president's vision commission (yes, there really was one). As he puts it, a cubic metre of regolith contains, besides the necessary oxygen, enough hydrogen, carbon, nitrogen, potassium and other trace elements to make two cheese sandwiches on rye, two colas and two large plums. Despite mythology to the contrary, though, the moon isn't actually made of cheese. So extracting this bounty is another matter. Whether the moon's natural resources can be used profitably remains, says Dr Spudis with nice understatement, a “key question”.

Those resources consist of a lot of rock, a lot of sunlight that could be used to generate electricity to process the rock and, at least in the dreams of many lunar scientists, some 20 billion tonnes of frozen water believed to lie at the bottoms of craters near the poles, where it is sheltered from the evaporative effects of sunlight. In addition to these goodies, the solar wind carries light elements such as helium to the moon's surface and leaves them there. Some visionaries think that this helium might find a market on Earth, though its main use would be in fusion reactors that do not yet exist. And there are also likely to be deposits of platinum and other valuable metals contained in asteroids that have crashed into the moon.

The least certain item on this list is the water. Evidence, but not proof, of its existence was found by two earlier missions. So the Lunar Reconnaissance Orbiter that NASA plans to launch in 2008 will search more thoroughly, and will also make detailed maps that should help to find good spots to land. Dr Spudis, though, already has a favourite. A crater at the south pole called Shackleton has a rim that is bathed in sunlight for more than three-quarters of the time (as opposed to half the time for most of the moon's surface). That makes it easier to generate electricity. The bottom of the crater, by contrast, is perpetually dark and, with luck, ice-bound.

It all sounds jolly ambitious. But establishing a human presence on the moon itself is not, actually, Mr Bush's ultimate ambition. He wants humans to explore the cosmos—or, at least, Mars. The moon is merely a stepping-stone; a place to teach people about living on other worlds. New survival technologies and systems developed on the moon will then be employed on Mars. These include better collaboration between people and robots, durable technologies for survival in hostile environments, better “closed-loop” recycling systems for the re-use of resources, and improved telemedicine. Practising on the moon makes sense because it is only three days travel from Earth.

According to Rick Tumlinson, president of the Space Frontier Foundation, a space advocacy group, this difference of emphasis between going to the moon for its own sake, and using it as a stepping-stone, illustrates a wider problem for NASA, which is that people disagree about what the vision really means. Since it was announced, says Mr Tumlinson, the vision has been an “all-spin zone”, with everyone spinning his own version. To some, it means mining the moon for helium or platinum. To others it is about building a lunar observatory. A third group wants to collect solar power and beam it to Earth. To the most ambitious, such as Mr Bush himself, it means that humanity is going to explore the rest of the solar system in person. And Mr Tumlinson's particular spin? “It's about permanence. We go to stay. It's about settlement and changing our culture. What you don't do is Apollo on steroids.”

Dr Griffin, therefore, has the difficult job of charting a course among these competing mini-visions. For, while Mr Bush and his vision are obviously going to be in the driving seat for now, that will not always be true. As Admiral Craig Steidle, the associate administrator of NASA's office of exploration systems, observes, the most difficult aspect of the vision is “sustainability”. By this he means keeping it intact through successive Congresses, administrations and NASA chiefs, who may have different visions, and also in the face of an increasingly vocal lobby that feels the private sector is being overlooked, visionwise.

A little science on the side, sir?

Perhaps, though, whether the vision can be realised or not is beside the point. The actual point is to give a drifting agency some focus, Mr Bush's initial goal. This re-focusing will have profound consequences for the agency's scientific mission—which some people feel is what it should be concentrating on, and isn't. Admiral Steidle told the meeting that the vision was “first and foremost” about advancing science. That, though, looks like disingenuous spin.

NASA will undoubtedly need science to achieve the vision, whatever it turns out to be. And there is undoubtedly lots of interesting science to be done on the moon. But if scientists were running the show, and acquisition of knowledge were NASA's top priority, they would be unlikely to spend $64 billion over the next 15 years on a manned trip to the moon.

Instead, scientists would prefer to build space telescopes to probe the origins of the universe and search for Earth-like planets around other stars, launch an unmanned mission to Jupiter's fascinating moon Europa, and fund the Glory mission, which is designed to answer crucial questions about the Earth's climate. And they would still have a lot of money left over.

But lunar science, and lots of it, is what they are going to get. For the real point of the vision, whatever form it takes in detail, is to put human exploration first and scientific discovery second. And that truly is back to the future for NASA, for the Apollo project had exactly the same priorities. Harrison Schmitt, Eugene Cernan's even more forgotten companion on the last Apollo mission, was the first and only scientist to make the trip. Even in the agency's heyday, NASA's scientists came second.

[427] Either spaceflight will be proven a successful revolution that opened the heavens to human use and habitation, or it will be proven an unsuccessful revolution that demonstrated in its failure the limits of technological advance .... If spaceflight does fail, its abandonment will represent a technological counterrevolution of great consequence, symbolizing the end of progress as it is understood today. - William Sims Bainbridge, The Spaceflight Revolution: A Sociological Analysis

America's space program was once a source of pride and inspiration. Now it is a shambles, its mission unclear, and its very existence at hazard. - Stuart F. Brown, "Space after the Race"

By the early 1970s, the spaceflight revolution was already gasping for breath. Born in the violence of the cold war, driven by the Sputnik hysteria, perverted by the specter of atomic apocalypse, and ultimately fed by the need to demonstrate in some dramatic - maybe even primal or mythic - way the essential superiority of the American democratic system over its supposedly entrenched and black-hearted communist enemies, the U.S. civilian space program of the 1960s represented an extraordinary national movement that could be sustained only for a brief but intense period when Americans were deathly afraid of the end of life as they knew it. Kennedy's moon shot was meant to alleviate deeply embedded fear and paranoia. By design, his Apollo program put America back on course as the world's indisputable technological leader and the guardian of a safer and more hopeful future.

Sunday, May 15, 2005

A recently rediscovered 400-meter Near-Earth Asteroid (NEA) is predicted to pass near the Earth on 13 April 2029. The flyby distance is uncertain and an Earth impact cannot yet be ruled out. The odds of impact, presently around 1 in 300, are unusual enough to merit special monitoring by astronomers, but should not be of public concern. These odds are likely to change on a day-to-day basis as new data are received. In all likelihood, the possibility of impact will eventually be eliminated as the asteroid continues to be tracked by astronomers around the world.

This object is the first to reach a level 2 (out of 10) on the Torino Scale. According to the Torino Scale, a rating of 2 indicates "a discovery, which may become routine with expanded searches, of an object making a somewhat close but not highly unusual pass near the Earth. While meriting attention by astronomers, there is no cause for public attention or public concern as an actual collision is very unlikely. New telescopic observations very likely will lead to re-assignment to Level 0 [no hazard]." This asteroid should be easily observable throughout the coming months.

The brightness of 2004 MN4 suggests that its diameter is roughly 400 meters (1300 feet) and our current, but very uncertain, best estimate of the flyby distance in 2029 is about twice the distance of the moon, or about 780,000 km (480,000 miles). On average, an asteroid of this size would be expected to pass within 2 lunar distances of Earth every 5 years or so.

Most of this object's orbit lies within the Earth's orbit, and it approaches the sun almost as close as the orbit of Venus. 2004 MN4's orbital period about the sun is 323 days, placing it within the Aten class of NEAs, which have an orbital period less than one year. It has a low inclination with respect to the Earth's orbit and the asteroid crosses near the Earth's orbit twice on each of its passages about the sun.

2004 MN4 was discovered on 19 June 2004 by Roy Tucker, David Tholen and Fabrizio Bernardi of the NASA-funded University of Hawaii Asteroid Survey (UHAS), from Kitt Peak, Arizona, and observed over two nights. On 18 December, the object was rediscovered from Australia by Gordon Garradd of the Siding Spring Survey, another NASA-funded NEA survey. Further observations from around the globe over the next several days allowed the Minor Planet Center to confirm the connection to the June discovery, at which point the possibility of impact in 2029 was realized by the automatic SENTRY system of NASA's Near-Earth Object Program Office. NEODyS, a similar automatic system at the University of Pisa and the University of Valladolid, Spain also detected the impact possibility and provided similar predictions.

December 24 Update: 2004 MN4 is now being tracked very carefully by many astronmers around the world, and we continue to update our risk analysis for this object. Today's impact monitoring results indicate that the impact probability for April 13, 2029 has risen to about 1.6%, which for an object of this size corresponds to a rating of 4 on the ten-point Torino Scale. Nevertheless, the odds against impact are still high, about 60 to 1, meaning that there is a better than 98% chance that new data in the coming days, weeks, and months will rule out any possibility of impact in 2029.

=====================Now if we just knew how to play space pin ball, maybe do some orbital mining. - LRK -

Sunday, May 01, 2005

A NASA mission dedicated to discovery of planets around others stars through observation of planets transits.

site exerpt

Kepler Mission: A Search for Terrestrial Planets It is a special purpose space mission in the NASA Headquarters Discovery Program for detecting terrestrial planets, that is, rocky and Earth-size, around other stars. How can extra solar terrestrial planets be detected? When a planet passes in front of its parent star, as seen by us, it blocks a small fraction of the light from that star. If the dimming is truly caused by a planet, then the transits must be repeatable. Measuring three transits all with a consistent period, duration and change in brightness provides a rigorous method for discovering and confirming planets planets even smaller than the...

The reference site for astronomer involved in the search for extrasolar planets.

site exerpt

Extrasolar Planets Encyclopaedia Other sites relevant to extrasolar planets update: 21 February 2005 Astronomers are encouraged to send their preprints to Jean.Schneider@obspm.fr (latex or postscript files) J. Schneider, Observatoire, 92195 Meudon, France Back to the Jean Schneider home page (updated 14 March 2002 The URL of this page is http www.obspm.fr/planets...

A brief history of the search for extrasolar planets, the findings and the future implications.

site exerpt

Extrasolar Planets This web page is an attempt to provide a review of humankind's quest for the discovery of planets outside our Solar System. In addition, a series of major web sites dealing with the search for extrasolar planets are listed. They are as follows: Discovery of Extrasolar Planets Extrasolar Planetary Systems Exoplanets The Extrasolar Planets Encyclopedia New Planets Known Planetary Systems Other Solar Systems Other Worlds, Distant Stars In addition to the above sites, NASA's Origins Program is attempting to answer an important question (among others Are there worlds like the Earth around nearby stars? If so, are they habitable, and...

UStAPS University of St.Andrews Planet Search Doppler surveys show that 1% of nearby main sequence stars host Hot Jupiters in 3-4 day 0.05 AU orbits. 10% of these will have orbits close enough to edge-on for the planet to transit in front of the star. Thus 1 in 1000 main sequence stars should wink every 3-4 days. Jupiter transiting the Sun produces a 1% wink easy to detect by differential CCD photometry. Lower mass main sequence stars are smaller, making their winks even deeper. There are many transit searches underway worldwide. St.Andrews is pursuing both Deep and Wide transit searches. DEEP SURVEY: We use the wide-field...

Full scale survey project for extra-solar planets. Overview and publications.

site exerpt

Extra-Solar Planet Search A series of preliminary tests were conducted to discover how to get the greatest sensitivity in our measurements. Now that those tests have been completed, we are expanding our efforts to begin a full scale survey project. This includes our joining the collaboration to operate the 1.3-m telescope on Kitt Peak. Overview Since the discovery of the first planet around 51 Pegasi, there has been an increased interest in the search for Extra-Solar planets. The links below will give you a brief overview of other, commonly used search methods, details of our method of choice (the transit method as well...

Designed for general astrophysics and search for signs of life on Earth-like planets orbiting nearby stars. It is a candidate cornerstone 9 for a European Space Agency mission in 2015.

site exerpt

Darwin Home Page space infrared interferometer planet finding mission Characterising planetary systems orbiting nearby stars Searching for signs of life on any Earth-like planets found Performing general astrophysics The European Space Agency has selected the InfraRed Space Interferometer Darwin as a mission for its Horizons 2000 programme. Selection of a launch date, probably at or after 2015, will be made on cost, science and technology grounds sometime before then. These pages give some information on this project, and thus are supplementry to the official ESA Darwin website. See also ESA Science and ESA RSSD Astrophysics. A description of the interferometer and the science may...

Will study all aspects of planets outside the solar system from their formation and development to the presence and features of those planets orbiting the nearest stars.

site exerpt

Planet Quest: Missions Terrestrial Planet Finder Package and announced an upcoming pre-proposal conference Full story The TPF general astrophysics whitepaper is now available Download (PDF, 2.1 MB) NASA has announced the Science Working Group for TPF-I and the Science and Technology Definition Team for TPF-C Full story Team lists The Terrestrial Planet Finder observatories will study all aspects of planets outside our solar system: from their formation and development in disks of dust and gas around newly forming stars to the presence and features of those planets orbiting the nearest stars; from the numbers at various sizes and places to their suitability as an abode for...

Extrasolar Planets The past four weeks have been heady ones in the planet-finding world: Three teams of astronomers announced the discovery of 12 previously unknown worlds, bringing the total count of planets outside our solar system to 145. FULL STORY Spitzer observes beginnings of mini solar system Interactive map of worldwide planet search projects d More News Former athlete flexes new muscles for planet search (January 19, 2005 Twice named All-American in track and field, he placed 12th in the 1992 U.S. Olympic Trials qualifier in high jump. Now, he has his sights set on even loftier goals building an instrument to...

Extrasolar Planet Detection with the AFOE The Advanced Fiber-Optic Echelle (AFOE) spectrometer is a fiber-fed, bench-mounted echelle spectrograph, located at the 1.5m telescope of the Whipple Observatory, near Tucson, Arizona.

site exerpt

Extrasolar Planet Detection with the AFOE Extrasolar planet detection is the search for planets around other stars than our Sun. Several techniques are being used to detect planets around other suns; they are discussed in a Scientific American Exploration Web page. The AFOE has been designed to provide the required precison and stability to detect the wobble induced on the star by the presence of a planet. Indeed, both the planet and the star revolve around their common center of gravity. While the center of gravity is very close to the center of the star, it is not exactly at the center of the star. Therefore...

Uncovering New Worlds Who else works on occulters? Publications 04-03-11 Other Technical Information Newsletters 02-01-07 What is UMBRAS? UMBRAS (Umbral Missions Blocking Radiating Astronomical Sources) is a technique and a class of space science missions. The UMBRAS goal is direct observation of planets around other stars Direct observation means images, photometry, and spectroscopy, as contrasted to the measurement of stellar reflex motion and variations in starlight flux used to demonstrate the discovery of extrasolar planets found so far. UMBRAS uses a companion spacecraft with a space telescope placed far from Earth. The companion spacecraft carries an occulting screen designed to reduce the glare...

Mission designed to provide improved resolution of closely spaced objects with comparable brightnesses (binary stars, microlensing events) and to facilitate separation of dim objects from nearby bright objects (such as planets around stars).

site exerpt

The Big Occulting Steerable Satellite S project are supported by NSF CAREER grant PHY-9600193 to CWRU, and by grants from the Department of Energy and NASA's Jet Propulsion Lab. Questions? Comments? e-mail us!...

The Microlensing Observations in Astrophysics (MOA) Project is a joint Japanese/New Zealand experiment established in 1995 to carry out astrophysical observations from New Zealand using `gravitational microlensing' and related techniques.

MIRLIN This was the first run with MIRLIN operating as a full IRTF facility instrument. The dot to the lower left of Jupiter is Ganymede. Jupiter, 7.85 181;m Jupiter, 17.2 181;m MIRLIN is now considered a part-time facility instrument at the IRTF; it is available to the IRTF community eight months of the year. Proposals to use it should be written in a manner similar to any other IRTF facility instrument. In particular, you do not need to include MIRLIN team members as collaborators on your proposals! Proposals to use the instrument at Palomar are welcome from anyone within the Palomar...

FAME is an astrometric satellite designed to determine with unprecedented accuracy the positions, distances, and motions of 40 million stars within our galactic neighborhood. It is a collaborative effort between the U.S. Naval Observatory (USNO) and several other institutions.

site exerpt

Full-sky Astrometric Mapping Explorer (FAME) Your browser does not support HTML frames! You need to upgrade! Download a copy of Netscape....

GEST, Gravitational Microlensing, Other Earths, and Life in the Universe

site exerpt

GEST As a planet system passes in front of a star, the star is distorted and magnified. GEST will image the time series of about 100 million of those stars. Is the Earth in the button gravitationally lensed? No. Not all distortions are due to gravitational lensing. Click here for more details on GEST PhysicsWeb news article on GEST...

The purpose of transitsearch.org is to coordinate and direct a cooperative observational effort which will allow experienced amateur astronomers and small college observatories to discover transiting extrasolar planets.

site exerpt

Transitsearch.org Jupiter type planets such as HD 209458 b, OGLE TR56-b, and TrES-1 have added an additional element of excitement to the quest for alien solar systems. Furthermore, the past several years have seen the introduction of highly affordable small telescopes equipped with sensitive CCD detectors. A large number of amateur astronomers and small colleges own observatories which, when properly configured, are capable of reliably detecting the periodic dimming that occurs when a close-in giant planet passes in front of its parent star as seen from Earth. This technique has been used by amateurs worldwide to detect the planetary transits of...